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Abstract:

A fluid transferer, including a volume changing part; a reciprocating
member configured to reciprocate to expand a volume of the volume
changing part to draw a fluid from an upstream side of a transfer
direction and compress the volume thereof to transfer the drawn fluid to
a downstream side thereof with pressure; and a drive controller
configured to control reciprocation of the reciprocating member such that
a time for compressing the volume of the volume changing part is longer
than a time for expanding the volume thereof.

Claims:

1. A fluid transferer, comprising: at least one volume changing part; at
least one reciprocating member configured to reciprocate to expand a
volume of the volume changing part to draw a fluid from an upstream side
of a transfer direction and compress the volume thereof to transfer the
drawn fluid to a downstream side thereof with pressure; and a drive
controller configured to control reciprocation of the reciprocating
member such that a time for compressing the volume of the volume changing
part is longer than a time for expanding the volume thereof.

2. The fluid transferer of claim 1, wherein the drive controller
comprises: a rotational drive source; a cam configured to rotate by drive
transmission from the rotational drive source and change a distance from
a rotational axis to a circumferential surface thereof according to a
position of the circumferential surface; a cam follower configured to
contact the circumferential surface of the cam, to be held so as not to
travel in a rotational direction thereof, to change a contact position on
the circumferential surface when the cam rotates, and to reciprocate one
time every time the cam rotates one time; and a reciprocation
transmitting member configured to transmit reciprocation of the cam
follower to the reciprocating member, wherein the cam comprises: an area
in which a distance from the rotational axis to the circumferential
surface becomes large in proportion to increase of a rotational angle of
the cam and a compression side allocated angle transmitting a motion to
compress the volume of the volume changing part is formed; and an area in
which a distance from the rotational axis to the circumferential surface
becomes small in reverse proportion to increase of a rotational angle of
the cam and a expansion side allocated angle transmitting a motion to
expand the volume of the volume changing part is formed, and wherein the
compression side allocated angle is larger than the expansion side
allocated angle.

3. The fluid transferer of claim 2, further comprising a compression
spring configured to press the cam follower to the circumferential
surface of the cam such that the cam follower follows the circumferential
surface of the cam at the expansion side allocated angle.

4. The fluid transferer of claim 2, wherein the cam rotates at from 20 to
90 rpm.

5. The fluid transferer of claim 1, comprising plural volume changing
parts and plural reciprocating members, wherein a flow path at the
upstream side of the transfer direction and a flow path at the downstream
side of the transfer direction are connected with each other.

6. The fluid transferer of claim 5, wherein the time for compressing the
volume of each of the volume changing parts is the same as the time for
expanding the volume thereof, and a total of which is one cyclic time,
and wherein the one cyclic time is divided by the number of the volume
changing parts to determine a phase difference of time, and with which
the reciprocating member for each of the volume changing parts
reciprocates.

7. The fluid transferer of claim 6, wherein the time for expanding the
volume of each the volume changing parts is shorter than the phase
difference of time and longer than 1/12 of the one cyclic time.

8. A powder filling apparatus, comprising: a powder basket configured to
include a powder; a powder container configured to contain the powder;
and a powder transferer configured to transfer the powder from the powder
basket to the powder container, wherein the powder transferer is the
fluid transferer according to claim 1.

9. The powder filling apparatus of claim 8, wherein the fluid transferer
is stopped when compressing the volume of the volume changing part but is
not stopped when expanding the volume thereof to stop filling the powder
container with the powder.

10. A fluid transfer method, comprising: expanding a volume of each of
plural volume changing parts with each of plural reciprocating members to
draw a fluid from an upstream side of a transfer direction; and
compressing the volume thereof with each of the plural reciprocating
members to transfer the drawn fluid to a downstream side thereof with
pressure, wherein a flow path at the upstream side of the transfer
direction and a flow path at the downstream side of the transfer
direction are connected with each other, a time for compressing the
volume of each of the volume changing parts is the same as the time for
expanding the volume thereof, and a total of which is one cyclic time,
and each of the reciprocating members reciprocates with a phase
difference.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application is based on and claims priority pursuant to
35 U.S.C. §119 to Japanese Patent Application No. 2011-104617, filed
on May 9, 2011, in the Japanese Patent Office, the entire disclosure of
which is hereby incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a fluid transferer transferring a
material having fluidity such as a powder, a fluid filling apparatus
having the fluid transferer, and to a method of transferring a fluid.

BACKGROUND OF THE INVENTION

[0003] Conventionally, a toner used in electrophotographic image formation
is filled in a toner container by a toner filling apparatus, and the
toner container is set in an image forming apparatus. In a toner filling
apparatus, as a toner transfer apparatus transferring a toner from a
toner basket including a toner for filling to the toner container, an
auger method rotating a spiral transfer member is known. However, in a
toner transfer apparatus using an auger method, the toner receives a
stress from friction with the rotating transfer member and possibly
deteriorates in quality.

[0004] Japanese Patent No. 4335216 discloses a toner transferer feeding
air to a toner in a toner basket to have higher fluidity and transferring
the toner to a toner container by a reciprocating pump. The reciprocating
pump includes a volume changing part changing its volume when a
reciprocating member reciprocates. The reciprocating pump expands a
volume of the volume changing part to introduce the toner from the toner
basket and compresses the volume thereof to transfer the introduced toner
to the toner container with pressure. Therefore, the reciprocating pump
prevents a toner from deteriorating due to friction with the transfer
member in the auger method.

[0005] However, a toner filling apparatus using a conventional
reciprocating pump has a problem of large unevenness in amounts of toner
filled in a toner container. This has the following reasons. The
reciprocating pump does not quickly stop transferring toner when tuned
off and transfers a small amount thereof. Therefore, the toner filling
apparatus using the reciprocating pump includes a weigher weighing the
toner container and stops the reciprocating pump when weighing a weight a
little lighter than a weight of the toner container filled with a desired
amount of toner.

[0006] A conventional reciprocating pump, when a period in which the
completely compressed volume changing part is expanded and completely
compressed again is one cycle, has the same time for expanding and
compressing the volume of the volume changing part in one cycle of the
reciprocation. The toner is fed to the toner container only when the
volume changing part is compressed, and this is why a time for
transferring the toner to the toner container is not longer than a half
of the cycle. Thinking of a transfer amount of the toner per time more
shortly divided from one cyclic time, when a time for transferring the
toner to the toner container is not longer than a half of the cycle, a
peak value of the transfer amount of the toner is larger than an average
thereof during the cycle.

[0007] The conventional reciprocating pump has large unevenness of the
amount of a toner fed after turned off according to timing of being
turned off during the cycle. Specifically, when the pump is turned off
just before the transfer amount of the toner has a peak value, the toner
in an amount of the peak value is fed and comparatively a large amount of
the toner is filled in the toner container. Meanwhile, when the pump is
turned off while or just before expanding the volume of the volume
changing part, almost no toner is fed after the pump is turned off. Thus,
comparatively a large amount of the toner is filled in the toner
container or almost no toner is fed after the pump is turned off, and
amounts of the toner filled in the toner container have large unevenness
after the filling process.

[0008] In order to prevent the unevenness of the amount of a toner filled
in the toner container, a toner transferring apparatus using
reciprocation and having a small difference between the peak value of the
transfer amount of the toner and an average thereof during the cycle is
required.

[0009] Further, when the peak value of the transfer amount of the toner is
smaller than the average thereof during the cycle, stresses on the toner
and each member forming the toner transferring apparatus can be
decreased. The objects of preventing unevenness of filling amount in a
filling apparatus and stresses on a fluid and each member forming a
transferring apparatus are not limited to a toner transferring apparatus.
Therefore, not only the toner transferring apparatus but also apparatuses
transferring other fluids such as powders, liquids and gases besides a
toner preferably have a small difference between a peak value of transfer
amount and an average thereof during a cycle.

[0010] Because of these reasons, a need exists for a fluid transferer
transferring a fluid using reciprocation and preventing an difference
between an average of a transfer amount of the fluid and a peak value
thereof during a cycle of the reciprocation.

SUMMARY OF THE INVENTION

[0011] Accordingly, one object of the present invention to provide a fluid
transferer transferring a fluid using reciprocation and preventing an
difference between an average of a transfer amount of the fluid and a
peak value thereof during a cycle of the reciprocation.

[0012] Another object of the present invention to provide a fluid filling
apparatus using the fluid transferer.

[0013] A further object of the present invention to provide a method of
transferring fluids.

[0014] These objects and other objects of the present invention, either
individually or collectively, have been satisfied by the discovery of a
fluid transferer, comprising:

[0015] a volume changing part;

[0016] a reciprocating member configured to reciprocate to expand a volume
of the volume changing part to draw a fluid from an upstream side of a
transfer direction and compress the volume thereof to transfer the drawn
fluid to a downstream side thereof with pressure; and

[0017] a drive controller configured to control reciprocation of the
reciprocating member such that a time for compressing the volume of the
volume changing part is longer than a time for expanding the volume
thereof.

[0018] These and other objects, features and advantages of the present
invention will become apparent upon consideration of the following
description of the preferred embodiments of the present invention taken
in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other objects, features and attendant advantages of the
present invention will be more fully appreciated as the same becomes
better understood from the detailed description when considered in
connection with the accompanying drawings in which like reference
characters designate like corresponding parts throughout and wherein:

[0020]FIG. 1 is a schematic view illustrating the toner filling apparatus
of the present invention;

[0021] FIGS. 2A, 2B and 2C are schematic front, top and side views,
respectively, illustrating the bellows pump of the present invention;

[0022]FIG. 3 is an enlarged view illustrating a cam included in the
bellows pump of the present invention;

[0024]FIG. 5 is an enlarged view illustrating a cam included in the
conventional bellows pump;

[0025]FIG. 6 is a cam diagram of the cam included in the bellows pump of
the present invention;

[0026]FIG. 7 is a cam diagram of the cam included in the conventional
bellows pump;

[0027]FIG. 8 is a diagram showing a relationship between a powder
discharge speed and a rotational angle of the bellows pump of the present
invention;

[0028]FIG. 9 is a diagram showing a relationship between a powder
discharge speed and a rotational angle of the conventional bellows pump;

[0029]FIG. 10 a diagram showing a relationship between a powder discharge
speed and a rotational angle of the bellows pump of the present invention
when the bellows are multiply located; and

[0030] FIG. 11 a diagram showing a relationship between a powder discharge
speed and a rotational angle of the conventional bellows pump when the
bellows are multiply located.

DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention provides a fluid transferer transferring a
fluid using reciprocation and preventing an difference between an average
of a transfer amount of the fluid and a peak value thereof during a cycle
of the reciprocation.

[0032] More particularly, the present invention relates to a fluid
transferer, comprising:

[0033] a volume changing part;

[0034] a reciprocating member configured to reciprocate to expand a volume
of the volume changing part to draw a fluid from an upstream side of a
transfer direction and compress the volume thereof to transfer the drawn
fluid to a downstream side thereof with pressure; and

[0035] a drive controller configured to control reciprocation of the
reciprocating member such that a time for compressing the volume of the
volume changing part is longer than a time for expanding the volume
thereof.

[0036] Hereinafter, an embodiment of a bellows pump 100 as the fluid
transferer of the present invention is explained.

[0037]FIG. 1 is a schematic view illustrating the toner filling apparatus
500 including a bellows pump 100 of the present invention. The toner
filling apparatus 500 feeds air from the bottom of a toner basket 10
storing a toner T in the direction of an arrow A to fluidize the toner T,
and fills a toner container 20 with the fluidized toner T in a specific
amount by the bellows pump 100.

[0038] FIGS. 2A, 2B and 2C are schematic front, top and side views,
respectively, illustrating the bellows pump 100 included in the toner
filling apparatus 500.

[0039] The toner basket 10 forms a toner fluidizing part taking air in
from the basket bottom 11 to fluidize the toner T stored therein. The
bellows pump 100 compresses and expands bellows 101 screwed into a valve
block 140 to transfer the toner T from the toner basket 10 in one
direction to the toner container 20 through two duckbill valves 110 and
120. A weigher 21 weighing the toner T filled in the toner container 20
is located at a position where the toner container 20 is placed to form a
toner weigher.

[0040] The toner basket 10 has a filter having openings smaller than a
particle diameter of the toner T at the basket bottom 11, through which
air is fed thereto to fluidize the toner.

[0041] The bellows pump 100 draws the fluidized toner T from the toner
basket 10 in the direction of an arrow B in FIG. 1, and transfers the
toner T to the toner container 20 in the direction of an arrow C.

[0042] The toner weigher weighs the toner transferred to the toner
container 20 by the weigher 21. Based on the weighing result, an
unillustrated controller stops the bellows pump 100 to fill the toner
container 20 with a predetermined amount of the toner T.

[0043] The bellows pump 100 includes two duckbill valves as check valves
to transfer the toner T in one direction, i.e., the first duckbill valve
110 at a drawing side and the second duckbill valve 120 at a discharge
side, and expands and compresses the bellows 101 to draw and discharge.

[0044] A cam 130 is located on a cam shaft 131 as a rotational shaft, and
a lever 102 having a cam follower 133 driven by the cam 130 transmits a
vertical reciprocation to a coupling rod 104 to rise and fall to expand
and compress the bellows 101. An end of a side the cam follower 133 of
the lever 102 is located on is pressed downward by a compression spring
134, and the cam follower 133 constantly contacts a circumferential
surface of the cam 130. The toner filling apparatus 500 rotates the cam
shaft 131 by an unillustrated driver such as a motor to fill and stops
rotating the cam shaft 131 to stop filling.

[0045] The cam follower 133 is fixed on an end of the lever 102 in its
longitudinal direction, and the coupling rod 104 is connected to the
other end thereof to connect the bellows 101 therewith. A reciprocating
member 105 of the bellows 101 is fixed at a lower end of the coupling rod
104, and an upper end thereof is turnably connected with the lever 102 by
a turnable connection member 106. The lever 102 is turnable around a
lever turning axis 103, and the coupling rod 104 transmits turning motion
of the lever 102 to the reciprocating member 105 as a vertical
reciprocation.

[0046] The bellows 101 has a structure of an accordion tube on which the
reciprocating member 105 is fixed. When the reciprocating member 105
descends, the accordion tube contracts and its inner volume contracts to
perform compression. When the reciprocating member 105 ascends, the
accordion tube expands and its inner volume expands to perform expansion.

[0047] The cam 130 rotates to change a distance from a center of the cam
shaft 131 to a point on the circumferential surface of the cam 130 where
the cam follower 133 contacts to. When the distance increases, the cam
follower 133 is pushed up relative to the cam shaft 131, and the
reciprocating member 105 connected with an end of the lever 102 through
the coupling rod 104 across the lever turning axis 103 is pushed down and
descends. When the distance decreases, an end of the lever 102 at its
side where the cam follower is located is pushed down by the compression
spring 134, and the reciprocating member 105 ascends.

[0048] When the cam 130 rotates to increase the distance from a center of
the cam shaft 131 to a point on the circumferential surface of the cam
130 where the cam follower 133 contacts to, the reciprocating member 105
descends to compress the bellows 101. The pressure of a space of the
valve block 140 connected with the bellows 101 while screwed thereinto
increases. Then, an end of the first duckbill valve 110 at drawing side
is blocked and a pipeline with a drawing side transfer pipe 12 is closed.
Then, an end of the second duckbill valve 120 at discharge side is pushed
outward to open, and the toner T in the bellows 101 is discharged to a
discharge side transfer pipe 22.

[0049] When the cam 130 rotates to decrease the distance from a center of
the cam shaft 131 to a point on the circumferential surface of the cam
130 where the cam follower 133 contacts to, the reciprocating member 105
ascends and the bellows 101 expands to depress the space of the valve
block 140. Then, an end of the second duckbill valve 120 at discharge
side is drawn inside to be closed, and the toner T is drawn into the
bellows 101 from a pipeline from the drawing side transfer pipe 12.

[0050] In order to precisely fill the toner container 20 with a toner, a
discharge speed variation in a compressional process of the bellows pump
100 is required to be small to improve filling preciseness of the toner
filling apparatus 500. Further, in order to prevent deterioration of a
toner, it is required that a stress to the toner when filled by the toner
filling apparatus 500 is prevented.

[0051] As mentioned above, the toner filling apparatus 500 of the present
invention has a means of mixing a gas in the toner T as a powder to be
fluidized and uses the bellows pump 100 having check valves such as
duckbill valves at a drawing and a discharge side. Then, the toner T
filled in the toner container 20 is weighed and the bellows pump 100 is
stopped to fill the toner container 20 with the toner T in a specific
amount.

[0052] Further, in the toner filling apparatus 500, the cam 130
transmitting reciprocation to the bellows 101 of the bellows pump 100 has
a shape such that a rotational angle of the cam 130 includes an angle
allocated to a compressional operation of the bellows 101 (compression
side angle) larger than an angle allocated to an expansional movement
(expansion side angle), and that the compressional speed is constant.

[0053] The cam 130 of the bellows pump 100 is explained. FIG. 3 is an
enlarged view illustrating the cam 130.

[0054] When the bellows pump 100 drives, the cam shaft 131 rotates to
rotate the cam 130 anticlockwise in the direction of an arrow D in FIG.
3. While the cam follower 133 contacts a circumferential surface of an
area of an angle α in FIG. 3, a distance r from a center 131p of
the cam shaft 131 to the point on the circumferential surface of the cam
130 where the cam follower 133 contacts to increases. Hereinafter, the
angle α is referred to as a compression side allocated angle
α. When the cam 130 rotates, while the cam follower 133 contacts a
circumferential surface of an area of an angle β in FIG. 3, the
distance r from the center 131p of the cam shaft 131 to the point on the
circumferential surface of the cam 130 where the cam follower 133
contacts to decreases. Hereinafter, the angle β is referred to as an
expansion side allocated angle β.

[0055] As FIG. 3 shows, the cam 130 has the compression side allocated
angle α fully larger than the expansion side allocated angle
β. When the cam 130 rotates in the direction of an arrow D, while
the cam follower 133 contacts the circumferential surface at the
compression side angle α, the distance r increases approximately in
proportion to a rotational speed. Since the distance r increases
approximately in proportion to the rotational speed, when the cam 130
rotates at a constant speed, while the cam follower 133 contacts the
circumferential surface at the compression side angle α, the
distance r increases approximately at a constant speed. Thus, the cam
follower 133 ascends at a constant speed, the reciprocating member 105
descends at a constant speed through the lever 102, and a volume of the
bellows 101 decreases at a constant speed. As a result, in the
compressional operation, the toner T in the bellows 101 is discharged to
the discharge side transfer pipe 22 at a constant speed.

[0057] Particularly, the fluid pressure methods, the fluid drop methods
and the bellows pump methods are known to increase fluidity of a toner to
make it easy to transfer the toner and prevent stress thereto.

[0058] Japanese Patent No. 4335216 discloses a toner filling apparatus
including a toner drawing means formed of a bellows pump as a
reciprocation pump and an air feeder to a powdery toner. The toner
filling apparatus feeds air in a toner basket including the powdery toner
to be fluidized and draws the fluidized toner by the bellows pump to
transfer the powdery toner from the toner basket to a toner container.
The bellows pump prevents stress to the powdery toner when transferred.
The toner filling apparatus disclosed in Japanese Patent No. 4335216 is
similar to the toner filling apparatus 500 in that a bellows pump is used
as a toner transfer apparatus. However, a conventional bellows pump has
large pulsation, and when a specific amount of a toner is filled in a
toner container such as a toner bottle, the amount of the toner filled in
the toner container largely varies according to timing of stopping the
bellows pump.

[0059] Japanese published unexamined application No. 2008-075534 uses a
lead screw to transmit reciprocation to a bellows, and rotates a drive
motor forward and reverse to elongate and contract the bellows to
transfer a fluid. The lead screw is capable of elongating and contracting
the bellows at a constant speed to discharge a toner at a constant speed.
However, when the drive motor is rotated forward and reverse at the same
speed, the amount of the toner filled largely varies according to timing
of stopping the bellows pump as well.

[0060] FIGS. 4A and 4B are schematic front and side views, respectively,
illustrating a conventional bellows pump 100. FIG. 5 is an enlarged view
illustrating a cam 130 included in the conventional bellows pump 100.

[0061] The conventional bellows pump 100 uses an eccentric cam as the cam
130 compressing and expanding the bellows 101 as FIGS. 4 and 5 show. The
eccentric cam is a circular disc having cam shaft penetrating though a
point far from a center thereof by an eccentric amount W.

[0062] In the conventional bellows pump 100 in FIG. 4, an upper end of the
coupling rod 104 is the cam follower 133, and the eccentric cam directly
transmits vertical reciprocation to the coupling rod 104. The eccentric
cam has the shape of a bilateral circle. Therefore, a ratio of a
compression side allocated angle α increasing a distance r from a
center 131p to a point on the circumferential surface of the cam 130
where the cam follower 133 contacts to and an expansion side allocated
angle β decreasing the distance r is 1/1.

[0063] A relation between the distance r and a rotational angle θ is
approximately a single chord curve having the following formula:

r=R0-W cos θ

wherein R0 is a radius of the circular disc and W is an eccentric
amount.

[0064] Compared FIG. 3 with FIG. 5, the conventional cam 130 in FIG. 5 has
a compression side allocated angle α and an expansion side
allocated angle β equal to each other, and the cam 130 of the
present invention in FIG. 3 has a compression side allocated angle
α fully larger.

[0065] Therefore, when the cam 130 has the same rotational speed, while
the cam 130 rotates one time, a time for the cam follower 133 contacts a
circumferential surface of the cam 130 of the present invention at the
compression side allocated angle α is longer than that of the
conventional cam 130. A discharge peak amount per unit time which is a
shorter divisional time from a time for the cam 130 to rotate one time
can be smaller than an average per unit time while the cam 130 rotates
one time.

[0066] The discharge peak amount is limited to perform discharge operation
more stable than the conventional bellows pump does.

[0067] In the bellows pump 100 in FIG. 2, the cam 130 elongating and
contracting the bellows 101 has the shape in which a compression side is
allocated longer than an expansion side. Therefore, one cyclic time of
reciprocation is the same, and when a toner transfer amount per one
cyclic time of reciprocation is the same, a compression speed can be
lowered than when the conventional eccentric cam is used and the
discharge amount of the toner T fed by the compression of the bellows 101
per unit time can be reduced. Further, the compression speed is
approximately constant. When the unillustrated cam shaft drive motor for
the bellows pump 100 is stopped when a desired amount of the toner is
being filled, an amount of the toner T fed until filling the toner T is
stopped varies less. Therefore, an amount thereof filled in the toner
container 20 has less unevenness. Further, a stress to the toner T is
reduced more than when the eccentric cam is used because of the lower
compression speed.

[0068] As FIG. 2 shows, the multiply-located bellows 101 of the bellows
pump 100 increases a transfer amount per time and averages a discharge
amount per time. An unillustrated cam shaft drive motor drives the cam
shaft 131 and plural (four in this embodiment) cams 130 are located on
the cam shaft 131. The cams 130 are located at a phase difference when
360[°] is divided by the number thereof (four in this embodiment).

[0069]FIG. 6 is a cam diagram showing a relationship between a rotational
angle θ and a distance r to an outer circumference of the cam 130
included in the bellows pump 100 of the present invention.

[0070] When the rotational angle θ is within the compression side
allocated angle α, the relationship between the rotational angle
θ and the distance r linearly goes up. Since the compression side
allocated angle α is longer than the expansion side allocated angle
β in the θ direction, a time for compression process
compressing a volume of the bellows 101 is longer than that for expansion
process expanding the volume thereof when the rotational speed is
constant.

[0071]FIG. 7 is a cam diagram showing a relationship between a rotational
angle θ and a distance r to an outer circumference of the cam 130
included in the conventional bellows pump 100 in FIGS. 4 and 5.

[0072] As FIG. 5 shows, the cam diagram of the conventional example is
approximately a single chord curve having the following formula:

r=R0-W cos θ

wherein R0 is a radius of the circular disc and W is an eccentric
amount.

[0073] Since the compression side allocated angle α and the
expansion side allocated angle β have the same length in the 0
direction, a time for compression process compressing the volume of the
bellows 101 and a time for expansion process expanding the volume thereof
have the same length when the rotational speed is constant.

[0074]FIG. 8 is a diagram showing a relationship between a discharge
speed of the toner T (hereinafter referred to as a powder discharged
speed) per unit time and a rotational angle θ of the bellows pump
100 of the present invention.

[0075] In the compression process in which the cam curve linearly
increases in the cam diagram, the bellows 101 decreases the volume at
almost a constant speed to discharge the toner T at almost a constant
speed.

[0076] In the expansion process, the second duckbill valve 120 closes a
pipeline with the discharge side transfer pipe 22 only to draw the toner
T.

[0077]FIG. 9 is a diagram showing a relationship between a powder
discharge speed and a rotational angle θ of the conventional
bellows pump 100 in FIGS. 4 and 5.

[0078] Since the conventional bellows pump 100 is pushed down by an
eccentric cam performing single chord movement, a discharge amount of the
powder pushed out by contraction of the bellows pump 100 has the shape of
a single chord and periodically changes. In the expansion process, the
second duckbill valve 120 closes a pipeline with the discharge side
transfer pipe 22 only to draw the toner T.

[0079] A time ratio of the compression process to the expansion process is
1/1, and a maximum value of the discharge speed is larger than that of
the bellows pump 100 of the present invention in FIG. 8.

[0080] Therefore, the conventional bellows pump 100 has large pulsation.
In contrast, the bellows pump 100 of the present invention has a peak of
discharge speed lower than the conventional one and can transfer a powder
with less pulsation.

[0081] When the bellows pump 100 is used to fill a toner as the toner
filling apparatus 500 in FIG. 1, when an amount of the toner filled is
measured by the weigher 21 to be close to a target value, it takes a time
since an unillustrated cam shaft drive motor stops until toner T
completely stops discharging. The conventional bellows pump 100 having
uneven discharge speed according to a rotational angle θ of the cam
130 has uneven discharged toner amount since the cam shaft drive motor
stops according to timing of stopping the cam shaft drive motor. On the
contrary, the bellows pump 100 of the present invention having less
uneven discharge speed prevents the uneven discharged toner amount since
the cam shaft drive motor stops.

[0082] When compressed, the toner T increases in density and is vulnerable
to stress, and a time for discharging can be prolonged and a peak of
discharging speed can be lowered, which is effective for products having
a low softening point.

[0083] The expansion process in which a reactive force due to compression
is released can draw the toner without harming the toner even in a
shorter time.

[0084]FIG. 10 a diagram showing a relationship between a powder discharge
speed and a rotational angle θ of the bellows pump 100 of the
present invention when the bellows 101 are multiply located.

[0085] When four cams 130 are located at a phase difference of
90[°] which is one fourth of 360[°], a relationship between
a powder discharge speed and a rotational angle θ of each of the
phases (1st to 4th phases) is shown in FIG. 10. A synthesized
discharge speed of the toner T transferred by each of the phases and a
rotational angle θ have a relationship as shown in FIG. 10, the
toner T can be discharged with less pulsation at all rotational angles
θ.

[0086] The toner filling apparatus 500 can precisely fill the toner
container 20 with a toner when using the bellows pump 100 of the present
invention.

[0087] FIG. 11 a diagram showing a relationship between a powder discharge
speed and a rotational angle θ of the conventional bellows pump 100
when the bellows 101 are multiply located.

[0088] When four cams 130 are located at a phase difference of
90[°] which is one fourth of 360[°], a relationship between
a powder discharge speed and a rotational angle θ of each of the
phases (1st to 4th phases) is shown in FIG. 11. A synthesized
discharge speed of the toner T transferred by each of the phases and a
rotational angle θ have a relationship as shown in FIG. 11, and a
pulsation having a peak of discharge speed occurs at 4 points.

[0089] The toner filling apparatus 500 cannot precisely fill the toner
container 20 with a toner when using the conventional bellows pump 100
because an amount of the toner T discharged varies until the toner T
completely stops discharging.

[0090] The conventional bellows pump 100 has four points where a pulsation
having a peak of discharge speed occurs even when the compression and
expansion phases of the four bellows 101 are shifted. However, a
difference between an average of transfer amount of a fluid during one
cycle of reciprocation and a peak thereof can be reduced more than a
bellows pump having one bellows 101 as FIG. 11 shows.

[0091] The present inventors filled the toner container 20 with 450 [g] of
a toner by the toner filling apparatus 500. The conventional bellows pump
100 had a standard deviation of 0.950 [g] and the bellows pump 100 of the
present invention had a standard deviation of 0.584 [g].

[0092] The above-mentioned fluid transferer of the present invention is a
bellows pump, but is not limited thereto. Other reciprocating pumps such
as diaphragm pumps can also be used as long as they have a volume
changing part due to reciprocation.

[0093] The bellows pump 100 which is the fluid transferer of the present
invention includes the bellows 101 which is a volume changing part
changing is volume due to reciprocation of the reciprocating member 105.
The bellows 101 expands its volume to draw the fluid toner T from the
toner basket 10 at an upstream side in a transfer direction, and
compresses its volume to transfer the drawn toner T downstream in the
transfer direction with pressure. In the bellows pump 100, as FIGS. 1 and
2 show, the cam 130, etc. in FIG. 3 controls reciprocation of the
reciprocating member 105 as a drive controller such that a time for
compressing the volume of the bellows 101 is longer than a timer for
expanding the volume thereof. The cam 130 in FIG. 3 can increase a time
for transferring the toner T with pressure per one cycle of compression
and expansion of the bellows 101. When a transfer amount of the toner T
per one cycle is the same, the transfer amount of the toner T per time
and a peak value thereof can be controlled because the time for
transferring the toner T with pressure is long. When a transfer amount of
the toner T per one cycle and a time for one cycle are the same, an
average of the transfer amount of the toner T per one cycle is the same.
Therefore, the peak value of the transfer amount of the toner T is
controlled to control a difference between the average of the transfer
amount of the toner T and the peak value of the transfer amount thereof
during one cycle of the reciprocation. Thus, when the unillustrated cam
shaft drive motor of the bellows pump 100 is stopped, uneven amount of
the toner T fed from the bellows 101 according timing thereof until
filling of the toner is stopped becomes less. Therefore, an amount of the
toner T filled in the toner container 20 varies less.

[0094] Drive controllers of the bellows pump 100 in FIGS. 1 and 2 includes
the unillustrated cam shaft drive motor as a rotational drive source, the
cam 130, the cam follower 133, the lever 102 and the coupling rod 104.
The cam 130 is rotates by drive transmission from the cam shaft drive
motor, and a distance from a rotational axis to a circumferential surface
of the cam changes according to a position on the circumferential
surface. The cam follower 133 contacts a circumferential surface of the
cam 130 and is held so as not to transfer in a rotational direction of
the cam 130, and a contact point on the circumferential surface changes
when the cam 130 rotates and reciprocates forward and reverse one time
every time the cam 130 rotates one time. The 102 and the coupling rod 104
are reciprocation transmission member transmitting reciprocation of the
cam follower 133 to the reciprocating member 105.

[0095] The cam 130 includes an area forming a compression side allocated
angle α and an expansion side allocated angle β in a
rotational direction. When the cam 130 has a rotational angle in a range
of the compression side allocated angle α, a distance from a
rotational axis to a circumferential surface becomes large in proportion
to increase of the rotational angle, and the cam 130 transmits a movement
to the reciprocating member 105 to compress the volume of the bellows
101. When the cam 130 has a rotational angle in a range of the expansion
side allocated angle β, the distance from the rotational axis to the
circumferential surface becomes small in proportion to increase of the
rotational angle, and the cam 130 transmits a movement to the
reciprocating member 105 to expand the volume of the bellows 101. The
compression side allocated angle α of the cam 130 is larger than
the expansion side allocated angle β thereof. Because of this, a
drive controller controlling reciprocation of the reciprocating member
105 such that a time for compressing the volume of bellows 101 is longer
than that for expanding the volume thereof can be used.

[0096] The drive controller is not limited thereto. As disclosed in
Japanese published unexamined application No. 2008-075534, when a lead
screw compresses and expands a bellows, a motor may have a different
rotational speed in forward and reverse rotation such that an expansion
time of the bellows is longer than a compression time thereof.

[0097] The bellows pump 100 in FIGS. 1 and 2 includes the compression
spring 134 pressing the cam follower 133 to a circumferential surface of
the cam 130 such that the cam follower 133 follows the circumferential
surface thereof at the expansion side allocated angle β. This is why
the drive controller transmits rotation of the cam 130 as reciprocation
of the cam follower 133.

[0098] The cam 130 of the bellows pump 100 of the present invention
preferably rotates at from 20 to 90 rpm. When less than 20 rpm, the toner
T possibly deteriorates in fluidity because air among the toner particles
deflates. When the toner T deteriorates in fluidity, the toner causes the
bellows 101 and the discharge side transfer pipe 22 to be blocked inside.
When faster than 90 rpm, the toner T receives more stress to agglutinate.

[0099] As FIG. 2 shows, the bellows pump 100 is formed of plural
parallely-located reciprocating members 105 and bellows 101, and the
drawing side transfer pipe 12 which is a flow path at an upstream side of
a transfer direction and the discharge side transfer pipe 22 which is a
flow path at a downstream side of the transfer direction are connected
with each other. Therefore, a transfer amount of the bellows pump 100 per
unit time can be increased without increasing a transfer amount of each
one of the bellows per unit time. When the transfer amount of each one of
the bellows 100 per unit time is not increased, the transfer amount per
unit time can be increased while preventing stress to the toner T when
transferred.

[0100] The bellows pump 100 in FIG. 2 has one cycle including one
expansion time for expanding the volume of the bellows 101 and one
compression time for compressing the volume thereof, and the expansion
time and the compression time of each of four bellows 101 are the same.
As FIG. 10 shows, the reciprocating member 105 corresponding to each of
the bellows 101 reciprocates with a phase difference obtained by dividing
one cyclic time by the number of the bellows 101. Namely, the cam 130 is
located with a phase difference of 90[°] which is obtained by
dividing 360[°] with 4. When the phase difference is obtained by
dividing one cyclic time by the number of the bellows 101, the bellows
pump 100 has almost a uniform powder discharge speed during one cycle as
the bottom line (synthesized) in FIG. 10 shows.

[0101] The expansion time of the bellows 101 of the bellows pump 100 is
shorter than a time of the phase difference. Even when one of the bellows
101 is in the process of expanding and is not transferring the toner, the
other bellows 101 is in the process of compressing and the bellows pump
100 constantly transfers the toner T. When the expansion side allocated
angle β is too small so as to shorten the expansion time, the cam
follower 133 cannot follow a circumferential surface of the cam 130.
Therefore, the expansion time is preferably longer than 1/12 of one cycle
time, i.e., the expansion side allocated angle β is preferably
larger than 30[°].

[0102] The toner filling apparatus 500 in FIG. 1 is a powder filling
apparatus transferring the toner T which is a powder for filling in the
toner basket 10 to the toner container 20 by a powder transferer to fill
the toner container 20 with the toner T. As the powder transferer, the
bellows pump 100 is used which is a fluid transferer of the present
invention.

[0103] The toner filling apparatus 500 includes a basket bottom 11 as a
fluidized bed feeding air to the toner T in the toner basket to increase
fluidity of the toner T. The toner filling apparatus 500 further includes
a valve block 140 drawing the fluidized toner T by a negative pressure
made by expansion of the bellows 101 and discharging the toner T by a
positive pressure made by compression thereof. The valve block 140
includes the first duckbill valve 110 and the second duckbill valve 120.
The second duckbill valve 120 closes a discharge pipe when the bellows
101 expands to make a negative pressure and closes a tapered end thereof.
The first duckbill valve 110 closes a drawing pipe when the bellows 101
compressed to make a positive pressure and closes a tapered end thereof.

[0104] The bellows pump 100 controls to transfer the fluidized toner T
with air in one direction by negative and positive pressures made by
compression and expansion of the bellows 101 and check valve effects of
the two duckbill valves.

[0105] The bellows pump 100 includes the coupling rod 104 transmitting
reciprocation to the reciprocating member 105 such that the bellows 101
compresses and expands, the cam 130 lifting and lowering the coupling rod
104, and the cam shaft 131 rotating the cam 130. Further, the bellows
pump 100 includes an unillustrated cam shaft drive motor rotating the cam
shaft 131. The cam 130 has such a shape that a distance from a center of
the cam shaft 131 to a circumferential surface at the compression aide
allocated angle α becomes large in proportion to a rotational
angle, and the reciprocating member 105 can be pushed down at a constant
speed and the volume of the bellows 101 can be compressed at a constant
speed. The compression aide allocated angle α corresponding to a
circumferential surface the cam follower 133 contacts when the
reciprocating member 105 is pushed down is larger than the expansion side
allocated angle β corresponding to a circumferential surface the cam
follower 133 contacts when the reciprocating member 105 is drawn up. The
toner filling apparatus 500 further includes the weigher 21 weighing the
toner filled in the toner container 20. When the toner container 20 is
detected to include a predetermined weight of the toner, based on the
weighing result of the weigher 21, the bellows pump 100 of the present
invention has less uneven transfer amount of the toner T after stopping
the cam shaft drive motor. The toner filling apparatus 500 prevents the
toner container 20 from being filled with uneven amount of the toner T.

[0106] When stopping the bellows pump 100 of the toner filling apparatus
500 to stop filling the toner container 20 with the toner T, it is
preferable to stop the bellows pump 100 when compressing the volume of
the bellows 101, but not to stop the bellows pump 100 when expanding the
volume thereof. Namely, the cam shaft drive motor is preferably stopped
when the cam follower 133 contacts a circumferential surface
corresponding to the compression side allocated angle α of the cam
130. When the cam shaft drive motor is stopped when expanding the volume
of the bellows 101, the toner T is not transferred or a little even if
transferred, which is less than when the cam shaft drive motor is stopped
when compressing the volume thereof and causes an uneven filled amount of
the toner T. Therefore, the cam shaft drive motor is stopped when
compressing the volume of the bellows 101 to prevent the toner container
20 from being filled with uneven amount of the toner T.

[0107] As a method of transferring the toner T by expanding the volume of
the bellows 101 changing the volume when the reciprocating member 105
reciprocates to draw the fluid toner T from an upstream side of a
transfer direction and compressing the volume of the bellows 101 to
transfer the drawn toner T to a downstream side of the transfer direction
with pressure, it is preferable that the reciprocating member 105 and the
bellows 101 are plurally located and that the reciprocating members 105
have phase differences. The bellows pump 100 plurally includes the
reciprocating member 105 and the bellows 101 and connects a flow path
from the toner basket 10 at the upstream side of the transfer direction
and a flow path to the toner container 20 at the downstream side thereof
with each other. The bellows pump 100 has one cycle including one
expansion time for expanding the volume of the bellows 101 and one
compression time for compressing the volume thereof, and the expansion
time and the compression time of each of the bellows 101 are the same.
One cycle time is divided by the number of bellows 101 to determine a
phase difference, and each of the reciprocating members 105 for each of
the bellows 101 reciprocates with the phase differences. Therefore, even
the bellows pump 100 including the bellows having the same expansion and
compression times, as the bottom diagram in FIG. 11 shows, prevents a
difference between an average and a peak value of transfer amount of the
toner T during one cycle of the reciprocation.

[0108] Having now fully described the invention, it will be apparent to
one of ordinary skill in the art that many changes and modifications can
be made thereto without departing from the spirit and scope of the
invention as set forth therein.